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TC Electronic RH750 ???!??

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#61
Eublet said:
I probably wouldn't do it, or at least don't push high volumes with this config. TC only supports 2.66 ohm nominal loads with their own RS cabinets since they know what the actual reactive load will be.
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This is actually not quite correct (tho it's not well publicized, so your comment is understandable). The secret sauce is that three of THEIR "8 ohm" cabs are actually still much closer to 4 ohms, and I'm guessing their impedance curve is safely at or above that over the nominal operational frequency range of a bass instrument application, which of course is by careful design... typical TC Electronic.

The beauty of these amps and why they seem so "loud" despite their "ratings" is their power management. This also gets into why we don't need to be quite as worried about running the minimum load on them to get them to be "loud".

I realize the tech details don't really mean much at the end of the day... it's really just all about how great they work, but FWIW, anyway.
 
#62
Eublet said:
Snapshots below of my RH450's "Streamliner" settings. It's even better sounding to me than the Streamliner. I can go for more bass, more mids, or whatever I want, with this as my starting point. And I'll be darned but the Tubetone even sounds better than the real tube pre on the Liner.

One picture is the level, the other with the Shift on shows the frequencies I'm manipulating.

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Saved! Thanks! :)
 
#63
My "Vegas-style" coverband played a high-profile gig for the American Cancer Society last Saturday. I played my Sadowsky J5 and FBass BN5 through the new RH750 into a Berg AE410. Primary effects were EHX BMS, TC Chorus, Maxon AF-9 and Boss OC-2.

I initially set everything flat, with enough gain to make the peak lamp light up when slapping the B string (which I don't often do). Just as it did in my little studio at home, the RH750 sounded like it had endless power. In fact, the soundguys commented a couple of times that I was pretty loud, but not to turn down because I sounded so good! (And I always bring good gear to my gigs, so they usually like my sound.)

During the gig, I got to play a little with SpectraComp, especially on the slap stuff. I've never been much of a compression enthusiast, but this one works really well! Lots of snap to the sound! Also, I love the tone controls. It was easy to dial in a little more bass for slap or more mid-punch for funky fingerstyle stuff.

TweeterTone is a great additional tone control, too. I know it's intended to be a "set-and-forget" control, but it's an easy way to go from a warm tone to really crisp and modern. I think I'd rather have that feature as a fifth tone control, with either SpectraComp or TubeTone accessible through the shift button.

I only used TubeTone once -- by accident! My cab started sounding distorted, like I had somehow blown a driver (which I've NEVER done in over 40 years of playing). I realized that, instead of turning up the compressor, I had turned up TubeTone! I felt much better after turning it back down.

I can tell that there's a lot to learn with this amp. It sounds very transparent when set flat, compared with other, more "voiced" heads from folks like Ampeg or Aguilar. As I become more familiar with the tone controls' semi-parametric capabilities and get a better handle on SpectraComp, I'll start using the memory presets to store my own favorite "voices."

So, assuming this amp proves to be road-worthy, I'm really happy with it!

Greg
 
#65
Vic said:
Saved! Thanks! :)
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You're welcome. One thing that I just realized isn't represented in these pictures is the Tubetone and Spectracomp settings I use. I turn both of them on, 3 LEDs only for each. You might want to put on some headphones to test the differences with these, as they really tend to stand out, but IME the Spectracomp and Tubetone don't play very nicely together at higher volumes, and either one used alone didn't really give me that clean Tube feel like the Streamliner has. But, running them both at this lower setting makes a big difference in the tone. The Spectracomp seems to round out the notes a bit and smoothen the top at this lower setting when the Tubetone is moderately engaged.

In fact, with headphones, you can hear an effect just by dialing in 1 click for each, as if the signal is rerouted through a new circuit that wasn't there before (or DSP subroutine in this case I suppose).
 
#70
Jarrett said:
Vic, can you elaborate/clarify?
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I hope this post is allowed, but I want to be backed up by some data I don't have handy right now, but know exists in the soon to be released Issue 6 of Bass Gear Mag. But the short version is what I posted. It's probably most accurate to say what's already been said in various posts even long ago... these heads do have a 4 ohm minimum, but that up to three of the RS cabs will stay safely above or close to that over the impedance curve of normal operating conditions.

The one thing I'll elaborate on is something I think folks gloss over too much... tho for understandable reasons... just to make conversations more reasonable... is the "x ohm" rating is the NOMINAL impedance of a cab given a certain frequency and maybe even amplitude. IT IS NOT the DC resistance of a cab. Most 8 ohm cabs measure around 6.3 ohms or so when using an ohmmeter, for example.

Now you start varying that frequency and the impedance varies based on lots of stuff... including cab porting/tuning. How a cab's impedance varies over a range of frequencies is called it's "impedance curve". As long as that curve doesn't threaten that 4 ohm floor too much, it's perfectly safe to operate the amp.

Hope this helps.
 
#72
Vic said:
I hope this post is allowed, but I want to be backed up by some data I don't have handy right now, but know exists in the soon to be released Issue 6 of Bass Gear Mag. But the short version is what I posted. It's probably most accurate to say what's already been said in various posts even long ago... these heads do have a 4 ohm minimum, but that up to three of the RS cabs will stay safely above or close to that over the impedance curve of normal operating conditions.

The one thing I'll elaborate on is something I think folks gloss over too much... tho for understandable reasons... just to make conversations more reasonable... is the "x ohm" rating is the NOMINAL impedance of a cab given a certain frequency and maybe even amplitude. IT IS NOT the DC resistance of a cab. Most 8 ohm cabs measure around 6.3 ohms or so when using an ohmmeter, for example.

Now you start varying that frequency and the impedance varies based on lots of stuff... including cab porting/tuning. How a cab's impedance varies over a range of frequencies is called it's "impedance curve". As long as that curve doesn't threaten that 4 ohm floor too much, it's perfectly safe to operate the amp.

Hope this helps.
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+1 And just to clarify, I'm sure there are MANY 8ohm cabs that would have the nominal impedance specs and impedance curves that would result in the TC heads working fine at the published 2.6 total nominal impedance when you combine three of them. However, since there is no way for either TC or the end user to be sure, they play it safe (and smart) by saying 'two ohm cabs from any manufacturer', but 'three of ours' if you want.
 
#73
KJung said:
...in the TC heads working fine at the published 2.6 total nominal impedance...
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Your post is generally correct, but I think you meant "minimum" not "nominal", and 4 ohms is the published minimum. Not 2.6. You're inferring the 2.6 from assuming three of their cabs rated at "8 ohms" equals that. I'm trying to pass on, that that's not actually the case, but the actual data to back me up (per my earlier post) is in the upcoming BGM issue. :)

But again the rest of your post is VERY correct in that there could be other cab combos that might be safe to run over the typical bassists frequency range, but they can't and won't try to figure out how to support that massive matrix of changing products, so they just do what makes sense... pair their own stuff up and support it. :)
 
#74
Vic, I'm not sure what you are saying is any different than what me and others have been saying about these cabs for a while. The reactive impedance of the cab is shown by the impedance curve. Maybe I'm misunderstanding you?
 
#75
Vic said:
Your post is generally correct, but I think you meant "minimum" not "nominal", and 4 ohms is the published minimum. Not 2.6. You're inferring the 2.6 from assuming three of their cabs rated at "8 ohms" equals that. I'm trying to pass on, that that's not actually the case, but the actual data to back me up (per my earlier post) is in the upcoming BGM issue. :)

But again the rest of your post is VERY correct in that there could be other cab combos that might be safe to run over the typical bassists frequency range, but they can't and won't try to figure out how to support that massive matrix of changing products, so they just do what makes sense... pair their own stuff up and support it. :)
Click to expand...

What I meant is that the 'published' impedance of any three 8ohm cabs is 2.6 ohms. That might or might not be the case... it could be higher or lower based on not only the nominal impedance (which I believe is kind of an averaging/summary of the impedance curve of the cab), but also the shape of the impedance curve, which I believe can be different even among cabs with similar nominal impedances.

We are all basically saying the same thing. My guess is that three of the TC 8ohm cabs results in a lower than 4ohm nominal impedance, but not all the way down to 2.67, still allowing the amp to operate safely (just guessing there).
 
#76
Eublet said:
Vic, I'm not sure what you are saying is any different than what me and others have been saying about these cabs for a while. The reactive impedance of the cab is shown by the impedance curve. Maybe I'm misunderstanding you?
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Yep. It's BOTH that and something else... the piece I'm trying to ALSO drive home is the cabs actually have a higher impedance (or at least DC ohm reading) than most (all?) other "8 ohm" cabs. That's why I kept putting that in quotes. The other part is the impedance curve thing, which I think you've explained very well and clearly understand.

The other part to the story is also what I've mentioned before, which is TC's amazing power management. They do such a great job of it that's why their heads seem to sound louder than a lot of other heads in their power class. This gets into the article our Technical Editor has in the upcoming issue. SUPER interesting stuff! This is a big part of why you can drive higher impedances and still seem plenty "loud".

But to say anything further, I'd need to back myself up with our TE's data, so that's why I'm trying not to say too much right now. Better yet, read it for yourself. Don't need me in the middle mucking things up. :)
 
#78
KJung said:
What I meant is that the 'published' impedance of any three 8ohm cabs is 2.6 ohms. That might or might not be the case...
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Right, and my main point is stating 2.6 ohms is confusing. That's why they never mention that. It's just safer and more correct to say 4 ohms, or up to three of their RS cabs. No need to complicate/confuse things with a number that likely doesn't apply in either case.
 
#80
Vic said:
Right, and my main point is stating 2.6 ohms is confusing. That's why they never mention that. It's just safer and more correct to say 4 ohms, or up to three of their RS cabs. No need to complicate/confuse things with a number that likely doesn't apply in either case.
Click to expand...

Actually, the confusion with this is that there are many heads that actually can run at 2.67 ohms safely (+ or -, depending on the cabs in question), and basically state that any three 8ohm cabs by any manufacturer are 'fine'. So, it is a bit of a strange thing (i.e., two of anyone elses, but three of ours, even though they state their cabs nominal impedance is 8ohms).

My guess is, this will continue to confuse customers as it has since the introduction of the RH450.
 
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